|Name||Clifton Suspension Bridge, Bristol, England|
|Owner||Clifton Suspension Bridge Trust set up under a Parliamentary Act of 1952|
|Design||I K Brunel|
|Design after 1861||John Hawkshaw, William Henry Barlow|
|Contractor||Cochrane Grove & Co, Dudley|
|When||1864 - 5 years after Brunel died|
|Where||Spans the Avon Gorge, Bristol, UK|
|Latitude||N 51 27' 18"|
|Longitude||W 2 37' 40"|
|Why||Connects Clfton to Leighwoods over the deep gorge|
|How to read the bridge||Read more about suspension bridges.....|
|Overall type||Hanging - Suspension Bridge|
|Main span||214.35 m. between piers but because the abutments project forwards the free suspended span is 193.85 m.|
|Height of towers/piers||26.2 m. - the pier on the Leighwoods side is about a metre lower than the Clifton side.|
|Height of roadway above high water level||75 m. - the deck has two approximately 1 metre deep wrought iron stiffening girders with truss cross girders under each hanger.|
Deck: wrought iron and timber planking
Chains: wrought iron links and hangers
In 1753 William Vick, an Alderman of Bristol, bequeathed £1,000 to the Merchant Venturers of Bristol to start a fund to build a bridge.
The English-French wars intervened so it wasn't until 1829 that a competition was announced. Thomas Telford was called in to make the final judgement.
Nearly all the entries were rejected - including the one from Brunel. Telford was asked to design a bridge and in 1830 an Act of Parliament was obtained. However his proposal for a bridge with towers built from the floor of the gorge was heavily criticised.
The Trustees decided to hold a second competition and tactfully sidelined Telford's design as being too costly.
This time Brunel won - eventually (initially he was in second place) and he was appointed. Work started in 1831 but then came the Bristol riots and the work stopped - for 5 years. Work began again but with setbacks (e.g. bankruptcy of a main contractor). By 1843 the piers were ready for the chains - but the money ran out.
The chains and plant were sold off to Brunel's Saltash Bridge project
After Brunel died in 1859, interest was revived. It so happened that the chains of Brunel's Hungerford Bridge in London were available as that bridge was being dismantled to make way for the Charing Cross Bridge designed by Barlow and Hawkshaw.
In 1860 a new bridge company was formed and a new scheme - based on that by Brunels but with some changes - was drawn up. Instead of two sets of chains on each side there are three supporting longitudinal wrought iron plate girders with truss cross girders. The hand rails are also lattice truss girders.
The bridge was completed in 1864.
|Grammar||Technically the bridge is a way of taking forces from up in the air down to the ground.
So imagine the flow of those forces through the structure.
Think of a truck standing on the brdge and how its weight is transmitted through the bridge to the ground.
Read more about suspension bridges.....
There is no direct vertical or torsional restraint of the deck at the abutments. The vertical loads are carried by the hangers and there is a short articulated span to allow for relative movements. There is some lateral and longitudinal restraint at each end. The wrought iron chains are supported on saddles on top of the towers with rollers allowing longitudinal movement - but with considerable friction There is a weight limit on the bridge of 2.5 tons axle weight, or four tons gross weight which effectively means cars and small goods vehicles. Toll barriers control the flow and there is a weighbridge in the road on both side.
The Clifton Bridge web site.
Barnes G W, Stevens T, The History of the Clifton Suspension Bridge, First published 1928.